Chapter 10: Liquids and Solids 10.1 Give explanations for the boiling points (0C) of the two sets of compounds: 10.2 Acetic acid (CH3CO2H, structure on next page) dimerizes in non-polar solvents: What would you predict the structure of its dimer to be? 10.3 Metallic gold crystallizes in a face-centered cubic lattice with its atoms touching along the diagonal of the face of the unit cell If the unit cell measures 4.07 x 10-10 m on a side, what is the apparent radius of the gold atom? 10.4 An unknown element crystallizes in a face-centered cubic lattice with a unit cell edge length of 352 pm The density of the metal is 8.92 g/cm3 What is the element? 10.5 Tungsten, W, is used in the filaments of light bulbs It forms a body-centered metallic lattice and has an atomic radius of 141 pm What is the length of the W unit cell? 10.6 Thorium, Th, has the largest molar mass of any element with a face-centered cubic lattice X-ray crystallography studies indicate the atomic radius of the element is 180 pm The molar mass of Thorium is 232 g/mol What is the volume of the Th unit cell? What is the density? Nguyen Tien Thao, Faculty of Chemistry, Hanoi College of Science, VNU 19 - Le Thanh Tong, Hoan Kiem, Hanoi, Vietnam Email: nguyentienthao@gmail.com 10.7 Europiu m, Eu, is the only rare-earth element that has a body-centered cubic lattice The density of Eu is 5.26 g/cm3 The molar mass of Europium is 152 g/mol What is the volume of the Eu unit cell? What is the atomic radius of Eu? 10.8 X-ray crystallography reveals that strontium has a face-centered cubic lattice with a unit cell length of 608 pm What is the atomic radius of Sr? 10.9 In the simple cubic form of manganese there are Mn atoms at the corners of a simple cubic unit cell that is 6.30 Å on edge (a) What is the shortest distance between centers of neigh- boring Mn atoms? (b) How many nearest neighbors does each atom have? 10.10 Silver crystals are face-centered cubic, with a cell edge of 4.086 Å (a) What is the distance between centers of the two closest Ag atoms? (b) What is the atomic radius of silver in this crystal? (c) How many nearest neighbors does each atom have? 10.11 Lithium bromide, LiBr, crystallizes in the NaCl face-centered cubic structure with a unit cell edge length of a = b = c = 5.501 Å Assume that the Br ions at the corners of the unit cell are in contact with those at the centers of the faces Determine the ionic radius of the Br ion One face of the unit cell is depicted in Figure: 10.12 Barium is the largest nonradioactive alkaline earth metal It has a bodycentered cubic unjt cell and a density of 3.62 g/cm3 What is the atomic radius of barium? 10.13 The molar heat of fusion, Hfus, of Na is 2.6 kJ/mol at its melting point, 97.5°C How much heat must be absorbed by 5.0 g of solid Na at 97.5°C to melt it? Nguyen Tien Thao, Faculty of Chemistry, Hanoi College of Science, VNU 19 - Le Thanh Tong, Hoan Kiem, Hanoi, Vietnam Email: nguyentienthao@gmail.com 10.14 The normal boiling point of ethanol, C2H5OH, is 78.3°C, and its molar heat of vaporization is 39.3 kJ/mol What would be the vapor pressure, in torr, of ethanol at 50.0°C? 10.15 Compare the amount of “cooling” experienced by an individual who drinks 400 mL of ice water (0.0°C) with the amount of “cooling” experienced by an individual who “sweats out” 400 mL of water Assume that the sweat is essentially pure water and that all of it evaporates The density of water is very nearly 1.00 g/mL at both 0.0°C and 37.0°C, average body temper- ature The heat of vaporization of water is 2.41 kJ/g at 37.0°C 10.16 Calculate the amount of heat, in joules, required to convert 180 grams of water at 10.0°C tosteam at 105.0°C Additional homework: Assignments in Chapter 10/ Chemistry (Steven S Zumdahl): 37-123 Nguyen Tien Thao, Faculty of Chemistry, Hanoi College of Science, VNU 19 - Le Thanh Tong, Hoan Kiem, Hanoi, Vietnam Email: nguyentienthao@gmail.com